diff --git a/abstract_client.cpp b/abstract_client.cpp
index 15c24c83e6..8d2a8ea7d8 100644
--- a/abstract_client.cpp
+++ b/abstract_client.cpp
@@ -201,6 +201,9 @@ void AbstractClient::setIcon(const QIcon &icon)
 
 void AbstractClient::setActive(bool act)
 {
+    if (isZombie()) {
+        return;
+    }
     if (m_active == act) {
         return;
     }
@@ -235,6 +238,17 @@ void AbstractClient::doSetActive()
 {
 }
 
+bool AbstractClient::isZombie() const
+{
+    return m_zombie;
+}
+
+void AbstractClient::markAsZombie()
+{
+    Q_ASSERT(!m_zombie);
+    m_zombie = true;
+}
+
 Layer AbstractClient::layer() const
 {
     if (m_layer == UnknownLayer)
diff --git a/abstract_client.h b/abstract_client.h
index 3c5ae809d0..ca923e325a 100644
--- a/abstract_client.h
+++ b/abstract_client.h
@@ -358,6 +358,7 @@ public:
         return m_icon;
     }
 
+    bool isZombie() const;
     bool isActive() const {
         return m_active;
     }
@@ -927,6 +928,7 @@ protected:
     void startAutoRaise();
     void autoRaise();
     bool isMostRecentlyRaised() const;
+    void markAsZombie();
     /**
      * Whether the window accepts focus.
      * The difference to wantsInput is that the implementation should not check rules and return
@@ -1237,6 +1239,7 @@ private:
     bool m_skipSwitcher = false;
     QIcon m_icon;
     bool m_active = false;
+    bool m_zombie = false;
     bool m_keepAbove = false;
     bool m_keepBelow = false;
     bool m_demandsAttention = false;
diff --git a/internal_client.cpp b/internal_client.cpp
index 4d94037e69..9e9e27c3e8 100644
--- a/internal_client.cpp
+++ b/internal_client.cpp
@@ -408,6 +408,7 @@ void InternalClient::showOnScreenEdge()
 
 void InternalClient::destroyClient()
 {
+    markAsZombie();
     if (isMoveResize()) {
         leaveMoveResize();
     }
diff --git a/x11client.cpp b/x11client.cpp
index f63ccc81c2..59e2f39852 100644
--- a/x11client.cpp
+++ b/x11client.cpp
@@ -146,7 +146,6 @@ X11Client::X11Client()
 
     info = nullptr;
 
-    deleting = false;
     m_fullscreenMode = FullScreenNone;
     hidden = false;
     noborder = false;
@@ -214,8 +213,7 @@ void X11Client::deleteClient(X11Client *c)
  */
 void X11Client::releaseWindow(bool on_shutdown)
 {
-    Q_ASSERT(!deleting);
-    deleting = true;
+    markAsZombie();
 #ifdef KWIN_BUILD_TABBOX
     TabBox::TabBox *tabBox = TabBox::TabBox::self();
     if (tabBox->isDisplayed() && tabBox->currentClient() == this) {
@@ -288,8 +286,7 @@ void X11Client::releaseWindow(bool on_shutdown)
  */
 void X11Client::destroyClient()
 {
-    Q_ASSERT(!deleting);
-    deleting = true;
+    markAsZombie();
 #ifdef KWIN_BUILD_TABBOX
     TabBox::TabBox *tabBox = TabBox::TabBox::self();
     if (tabBox && tabBox->isDisplayed() && tabBox->currentClient() == this) {
@@ -1099,7 +1096,7 @@ void X11Client::destroyDecoration()
         move(grav);
         if (compositing())
             discardWindowPixmap();
-        if (!deleting) {
+        if (!isZombie()) {
             emit geometryShapeChanged(this, oldgeom);
         }
     }
@@ -1533,7 +1530,7 @@ void X11Client::doSetShade(ShadeMode previousShadeMode)
 
 void X11Client::updateVisibility()
 {
-    if (deleting)
+    if (isZombie())
         return;
     if (hidden) {
         info->setState(NET::Hidden, NET::Hidden);
@@ -1579,7 +1576,7 @@ void X11Client::updateVisibility()
 void X11Client::exportMappingState(int s)
 {
     Q_ASSERT(m_client != XCB_WINDOW_NONE);
-    Q_ASSERT(!deleting || s == XCB_ICCCM_WM_STATE_WITHDRAWN);
+    Q_ASSERT(!isZombie() || s == XCB_ICCCM_WM_STATE_WITHDRAWN);
     if (s == XCB_ICCCM_WM_STATE_WITHDRAWN) {
         m_client.deleteProperty(atoms->wm_state);
         return;
@@ -2202,7 +2199,7 @@ void X11Client::fetchIconicName()
 
 void X11Client::setClientShown(bool shown)
 {
-    if (deleting)
+    if (isZombie())
         return; // Don't change shown status if this client is being deleted
     if (shown != hidden)
         return; // nothing to change
diff --git a/x11client.h b/x11client.h
index 817aa69e04..8bf6f4c4d8 100644
--- a/x11client.h
+++ b/x11client.h
@@ -491,7 +491,6 @@ private:
     xcb_window_t m_transientForId;
     xcb_window_t m_originalTransientForId;
     X11Client *shade_below;
-    uint deleting : 1; ///< True when doing cleanup and destroying the client
     Xcb::MotifHints m_motif;
     uint hidden : 1; ///< Forcibly hidden by calling hide()
     uint noborder : 1;
diff --git a/xdgshellclient.cpp b/xdgshellclient.cpp
index d8a1655cb4..5ca01e3074 100644
--- a/xdgshellclient.cpp
+++ b/xdgshellclient.cpp
@@ -188,7 +188,7 @@ bool XdgSurfaceClient::stateCompare() const
 
 void XdgSurfaceClient::scheduleConfigure()
 {
-    if (isClosing()) {
+    if (isZombie()) {
         return;
     }
 
@@ -518,7 +518,7 @@ void XdgSurfaceClient::addDamage(const QRegion &damage)
 bool XdgSurfaceClient::isShown(bool shaded_is_shown) const
 {
     Q_UNUSED(shaded_is_shown)
-    return !isClosing() && !isHidden() && !isMinimized();
+    return !isZombie() && !isHidden() && !isMinimized();
 }
 
 bool XdgSurfaceClient::isHiddenInternal() const
@@ -564,14 +564,9 @@ void XdgSurfaceClient::internalHide()
     emit windowHidden(this);
 }
 
-bool XdgSurfaceClient::isClosing() const
-{
-    return m_isClosing;
-}
-
 void XdgSurfaceClient::destroyClient()
 {
-    m_isClosing = true;
+    markAsZombie();
     m_configureTimer->stop();
     if (isMoveResize()) {
         leaveMoveResize();
@@ -1076,7 +1071,7 @@ bool XdgToplevelClient::acceptsFocus() const
             return m_plasmaShellSurface->panelTakesFocus();
         }
     }
-    return !isClosing() && readyForPainting();
+    return !isZombie() && readyForPainting();
 }
 
 Layer XdgToplevelClient::layerForDock() const
@@ -1427,7 +1422,7 @@ void XdgToplevelClient::installServerDecoration(ServerSideDecorationInterface *d
     m_serverDecoration = decoration;
 
     connect(m_serverDecoration, &ServerSideDecorationInterface::destroyed, this, [this] {
-        if (!isClosing() && readyForPainting()) {
+        if (!isZombie() && readyForPainting()) {
             updateDecoration(/* check_workspace_pos */ true);
         }
     });
@@ -1449,7 +1444,7 @@ void XdgToplevelClient::installXdgDecoration(XdgToplevelDecorationV1Interface *d
     m_xdgDecoration = decoration;
 
     connect(m_xdgDecoration, &XdgToplevelDecorationV1Interface::destroyed, this, [this] {
-        if (!isClosing() && m_isInitialized) {
+        if (!isZombie() && m_isInitialized) {
             updateDecoration(/* check_workspace_pos */ true);
         }
     });
diff --git a/xdgshellclient.h b/xdgshellclient.h
index 9eb216cea3..2e542f4aa5 100644
--- a/xdgshellclient.h
+++ b/xdgshellclient.h
@@ -82,7 +82,6 @@ public:
     QRect requestedClientGeometry() const;
     QSize requestedClientSize() const;
     QRect clientGeometry() const;
-    bool isClosing() const;
     bool isHidden() const;
 
 protected:
@@ -121,7 +120,6 @@ private:
     QRect m_requestedFrameGeometry;
     QRect m_bufferGeometry;
     QRect m_requestedClientGeometry;
-    bool m_isClosing = false;
     bool m_isHidden = false;
     bool m_haveNextWindowGeometry = false;
 };